As a structure of a solid-state imaging unit, there is proposed a solid-state imaging unit of a back-surface illumination type in which a photodiode is formed on a surface, of a base, opposite from a surface where electrodes, wirings, etc. are formed, and light is applied from a back surface to perform photoelectric conversion (for example, see Patent Literature 1). FIG. 20 illustrates a pixel structure of this solid-state imaging unit of a back-surface incidence type. In the solid-state imaging unit illustrated in FIG. 20, a top surface side of a semiconductor base 41 serves as a light incident surface, and a surface opposite therefrom serves as a circuit formation surface. The pixel structure of the solid-state imaging unit includes a photodiode PD as a photoelectric conversion section 42 in the semiconductor base 41. Further, a reflection plate 44 formed of a metal film is formed on the circuit formation surface. The reflection plate 44 reflects light that has passed through the semiconductor base 41, and causes the reflected light to enter the photoelectric conversion section 42 again. Thus, sensitivity of the solid-state imaging unit is improved.